1. Field of the Invention
The present invention relates to a printer.
2. Description of the Prior Art
FIG. 1 is an exploded perspective view of a conventional heat transfer color printer. As shown in the drawing, the conventional heat transfer color printer comprises the following components or portions: a lower cabinet 1; a circuit portion 2; a power supply panel 3; a pinch roller 4; a capstan roller 5, against which the pinch roller 4 is adapted to abut to impart a driving force to the same; a platen roller 6, which, together with the pinch roller 4 and the capstan roller 5, constitutes a paper feeding mechanism; a main motor 7 for driving the pinch roller 4 and the platen roller 6; a pinch lever 8 adapted to be interlinked with the movement of a cam to cause the pinch roller 4 to be brought into contact with the capstan roller 5 or to cancel the contact thereof; a release roller 9 for releasing an ink film from paper; a paper feed roller 10 for bringing the paper into contact with the platen roller 6; a paper guide 11 for guiding the paper; and a paper support 12 for supporting the paper wound in the form of a roll. The printer further comprises a cover frame 13; a lock lever 14; a lock lever shaft 15, which engages or disengages with the lock lever 14 to open or close the cover frame 13; a ribbon feed gear 16 disposed on the cover frame 13 and adapted to effect positioning of one end of a ribbon feed; a ribbon holder 17 similarly disposed on the cover frame 13 and adapted to impart a pressing force against the other end of the ribbon feed; a head holder 18; a head 19 secured to the head holder 18; a head arm 20 which is interlinked with the operation of a cam and to which the head 19 is secured; a cooling fan 21 for radiating heat from the main motor 7, the circuit portion 2, and the like; an operation panel 22; a top cover 23; and an upper cabinet 24.
In the conventional heat transfer color printer, the paper feeding and printing are carried out in the manner illustrated in FIGS. 2a and 2b.
At the time of printing, as shown in FIG. 2b, paper 25 is gripped by the capstan roller 5 and the pinch roller 4 and rotates in the direction of the arrow B. At this time, the head 19 is pressed by the platen roller 6, which races clockwise by means of a one-way clutch (not shown in this drawing) and is rotated by the paper 25 only by an amount of feeding by the capstan roller 5.
Meanwhile, at the time of paper feeding, as shown in FIG. 2a, the capstan roller 5 and the pinch roller 4, while gripping the paper, rotate in the direction of the arrows a, b. At this time, the head 19 is located at a position spaced apart from the platen roller 6, and the paper 25 is gripped by the platen roller 6 and the paper feed roller 10 and is driven counterclockwise by the one-way clutch by means of the platen roller 6 which is connected with the capstan roller 5 via gears.
Incidentally, yellow magenta, and cyan are arranged on an ink film 27 sequentially for each image plane, and the above-described operation is repeated three times to effect color printing.
However, with the arrangement shown in FIGS. 2a and 2b, at the time when the paper 25 is set between the platen roller 6 and the pinch roller 4, if the paper 25 is set diagonally with respect to the direction A or B, or if it is set with the paper 25 slackened between the pinch and capstan rollers 4, 5 on the one hand, and the platen roller 6 on the other, the state of the diagonal setting and slackening of the paper 25 remain as they are since both the platen roller 6 and the pinch roller 4 are rotatively driven at the time of paper feeding and printing. For this reason, when printing is effected, there has been a drawback in that diagonal printing and misalignment of printing can occur.